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Finding the Fourth Proportional to 128.28, 191.35 and 116.12

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Solution

The fourth proportional to 128.28, 191.35 and 116.12 is: 173.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.28 : 191.35 = 116.12 : x
  2. Step 2: Convert to fraction form
    128.28/191.35 = 116.12/x
  3. Step 3: Cross multiply
    128.28x = 191.35 × 116.12
  4. Step 4: Simplify right side
    128.28x = 22,219.56
  5. Step 5: Solve for x
    x = 22,219.56/128.28
  6. Step 6: Final answer
    x = 173.21

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.